I am eating some pig now as I write. It was a real, not fictional, pig.
If you say that I shouldn't have eaten it, you are saying you prefer
the counterfactual world where that pig never existed. Your argument
is that, in that counterfactual world, the real pig in front of me would
then be fictional, and so you wouldn't have to worry about its "desires."
But I am now taking into account the *real* "desires" of a real pig I
am eating. I judge it preferred to live than to not exist, even if that
meant being eaten in the end.

>You will be unsurprised to hear that I wouldn't argue this. If you-today>are in the process of committing suicide, because you are suffering the>extreme irremediable pain of some terminal condition, say, should I>frustrate your effort on the assumption that you-tomorrow might regret>being dead? Should I privilege the you-tomorrow who would regret your>decision over the you-tomorrow who would not regret it and simply try>again? On what grounds?

I don't know which side you should come down on, but I do think you
should at least consider the desires of the me-tommorow in your analysis.